WYSS Institute for Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts, USA.
Biophys J. 2012 Jul 18;103(2):255-64. doi: 10.1016/j.bpj.2012.05.025. Epub 2012 Jul 17.
Grazing incidence x-ray diffraction measurements were performed on single hydrated bilayers and monolayers of Ceramide/Cholesterol/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocyholine at varying concentrations. There are substantial differences in the phase and structure behavior of the crystalline domains formed within the bilayers relative to the corresponding monolayers, due to interactions between the opposing lipid leaflets. Depending on the lipid composition, these interactions lead to phase separation and formation of cholesterol crystals. The cholesterol and ceramide/cholesterol mixed phases were further characterized at 37°C by immunolabeling with specific antibodies recognizing ordered molecular arrays of cholesterol. Previous studies have shown that cholesterol may nucleate in artificial membranes to form thick two-dimensional bilayer crystals. The study herein demonstrates further growth of cholesterol into three-dimensional crystals. We believe that these results may provide further insight into the formation of cholesterol crystals in early stages of atherosclerosis inflammation.
掠入射 X 射线衍射测量在不同浓度下对水合双层和单层神经酰胺/胆固醇/1-棕榈酰-2-油酰基-sn-甘油-3-磷酸胆碱进行了研究。由于 opposing lipid leaflets 之间的相互作用，形成于双层中的结晶域的相态和结构行为与相应的单层有很大的不同。这些相互作用导致相分离和胆固醇晶体的形成，具体取决于脂质组成。胆固醇和神经酰胺/胆固醇混合相在 37°C 下进一步通过与特异性识别胆固醇有序分子排列的抗体进行免疫标记进行表征。先前的研究表明，胆固醇可能在人工膜中成核以形成厚的二维双层晶体。本研究进一步证明胆固醇向三维晶体生长。我们相信这些结果可能为动脉粥样硬化炎症早期胆固醇晶体的形成提供进一步的见解。
